This invention relates to an outside mirror for a motor vehicle comprising a wiper means which includes a liquid spraying means with at least one spraying nozzle on an edge of the mirror casing, as well as a wiper blade which is movable substantially over the whole mirror in an orientation remaining always in parallel with itself.
An outside mirror of a motor vehicle will only fulfill its intended function if it gives the driver a good view of the rear area behind the vehicle, with the area being predetermined by adjustment of the mirror. A good general view of the rear traffic situation, e.g., approaching cars which just start a passing maneuver, is often of decisive importance to safe driving.
When an outside mirror is soiled, misted with moisture or covered with rain drops, it can no longer offer high visibility to a driver toward the rear of the vehicle and sources of danger may remain undiscovered. In critical situations, a driver will try to gain the necessary visibility by turning around so as to be able to look back over his shoulder. This behavior, in turn, entails the risk of a collision. A careful, responsible driver will therefore stop the car and clean the soiled outside mirror by hand. This may possibly be required several times under adverse weather and road conditions.
German patent DE 34 25 121 A1 discloses an outside mirror of the above-mentioned kind. A pneumatic piston/cylinder assembly, which is arranged inside an externally exposed recess of the mirror casing, is provided as a drive means for the wiper blade. The cylinder casing with the wiper blade is moved upwards and downwards by control of a compressed air supply, the cylinder casing being extended beyond the upper edge of the mirror casing. This pneumatic drive means is very troublesome from a technical point of view and subject to failure because the piston/cylinder assembly is exposed to the outside of the mirror, and it may become inoperative, either due to dirt or snow entering into the recess or due to frosting of the piston rod. Moreover, the cylinder casing, which extends beyond the mirror casing, presents a safety risk.
The upper edge of the casing of this known outer mirror has mounted thereon a spraying nozzle for spraying a cleaning liquid onto the mirror casing. Since the wiper blade performs an upward and downward movement, the mirror cannot be cleaned in an efficient way because the wiper blade repeatedly distributes the liquid together with the dirt that has been removed from the mirror surface over the mirror surface during its upward movement.
The cleaning liquid is supplied from a conduit connected to a liquid tank positioned inside the vehicle. It is difficult to connect the outside mirror to the liquid tank because the flexible supply tube must not be exposed to the outside of the vehicle.
German journal "Kraftfahrzeugtechnik" 8/69 discloses a rear-window cleaning process wherein the wiper blade extends over the total height of the rear window and is guided along guide rails in a horizontal direction over the total width of the window. More specific details of the drive means are not disclosed.
German patent DE 37 21 370 A1 discloses an outside rear view window for automotive vehicles including a washing device which only contains spraying nozzles for spraying washing liquid onto the mirror surface. The outside rear view window is not equipped with a wiper and drive means, so that the mirror surface cannot be cleaned in an efficient way.
German patent DE 37 15 798 A1 deals with an optoelectronic device for sensing dirt on transparent protective panes and for initiating cleaning measures, such as the front panes of vehicles and ships as well as protective panes in industrial plants.